Shot shell



Feb 1949- w. L..FlNLAY ET AL 2,462,312

SHOT SHELL Filed Aug. 2, 1944 INVENTORS. WALTER L. F/NLAY y G/LBERT E. HUTCH/NSON Patented Feb. 22, 1949 SHOT SHELL Walter L. Finlay, Fairfield, and Gilbert E. Hutchinson, Bridgeport, Conn, assignors to Remington Arms Company, Inc, Bridgeport, Conn, a

corporation of Delaware Application August 2, 1944, Serial No. 547,696

4 Claims.

This invention relates to ammunition, particularly to paper body shot shells, and contemplates a shot shell of improved ballistics and superior stability.

In the drawings:

Fig. 1 is a sectional elevation of a shot shell including the improved wad column of the invention and a crinkled skirted base Wad.

Fig. 1a is a sectional elevation of the shot shell of Fig. l but provided with an alternative end closure.

Fig. 2 is a fragmentary sectional elevation of a shot shell comprising an alternative embodiment of the invention.

Fig. 3 is a sectional elevation of the paper body of a shot shell showing another alternative embodiment of certain features of the invention.

Fig. 4 is a perspective View of a base wad partially formed from laminations of crinkled paper.

Shot shells as ordinarily manufactured comprise a metallic cap or head into which is inserted a tubular paper body that has been heavily impregnated with a moisture-repellent material, usually paraifin wax. A base wad, which may be of wound paper of suitable properties or other desirable material appropriately processed, is firmly pressed into the tube adjacent the head, and serves to join the head and body and to shield the relatively thin metal of the head from the high pressures developed in firing. A battery cup including a primer is pressed into a suitable aperture in head and base wad. An appropriate charge of propellent powder is placed in the shell adjacent the head, and filler wads including a cardboard over-powder wad are placed over the powder, separating the powder from the shot charge which occupies the forward part of the shell. One method of closing the open ends of such shot shells is to insert a cardboard top wad, having a diameter substantially equal to the interior diameter of the body into the shell over the shot charge, and to crimp the end portion of the body over such top wad by turning or rolling a short section thereof inwardly and back through 180, so that the end of the inturned portion or roll crimp rests on the outer surface of the top wad. A preferred method of closing is illustrated in the patent to Finlay et. al. No. 2,242,907, May 20, 1941. According to this method, the end portion of the body is creased and turned inwardly and itself forms a flat closure integral with the body, which closure is subsequently sealed by affixing thereto an exterior sealing disk. Shot shells closed in this manner do not utilize a top wad, and hence give better patterns than shot shells closed by means of the more conventional top wad and roll crimp, for the reason that in shot shells of the latter construction, hereinafter termed roll crimp shells, the top wad is ejected from the gun barrel in the same substantially perpendicular relation thereto which it has in the shot shell and hence tends to obstruct the forward movement of the central portion of the shot mass, deflecting the shot laterally and producing ring or blown patterns. On the other hand, the flight of the shot charge of a shell having an integral end closure, hereinafter termed a fiat top shell, is unobstructed and unimpeded by a top wad and hence produces superior patterns.

The present invention is the result of efiorts to further improve the ballistics of shot loads and particularly the shot loads of flat top shot shells.

It has long been believed that leakage of powder gas past the filler wads which separate the powder charge from the shot charge is a factor not only in producing blown or ring patterns but in leading. The latter term refers to the adherence of particles of lead to the gun bore. Poorly fitted or poorly constructed filler wads are believed to permit the escape of substantial quantities of hot powder gas past the wad column and into the shot charge, producing shot turbulence and a certain amount of fusion which causes small particles of lead to be abraded or fused 0 3 from the shot and to adhere to the gun bore. It has also been reasoned that poor or blown patterns are produced by the leakage of gases past the wad column causing a scattering of the shot charge. While these possibilities have been known and recognized in a somewhat academic way, their full importance has not been appreciated prior to the present invention.

In the development of the present invention, it was discovered that the dispersion of the shot charge of a roll crimp shell is due primarily to the presence of the top wad moving forwardly in advance of the shot charge and obstructing its flight; and this phenomenon was the more marked as the gas sealing properties of the wad column were increased. It was subsequently found that in roll crimp shells optimum patterns were produced when a wad column was used which permitted the escape of gas for the reason that the escaping gases effectively displaced the relatively light cardboard top wad from the path of the shot. It must be concluded, therefore, that a certain amount of gas must be permitted to escape past the wad column of the roll crimp type of shot shell to avoid spread patterns. Gas leakage is undesirable, since it ,causes barrel leading, and, if excessive, tends to scatter the shot. The present invention contemplates a greatly improved wad which is both gas sealing and cushioning, and is especially adapted, though not limited to shells closed without a top wad.

Where a closepatternis not-a-consideration as, for instancawhen 'a-scattered sh'ot charge iszdesired, a wad column having improved gas sealing properties may be used to advantage in the roll crimp type of shell, as shown in Fig. 1a. Heretofore, scatter loads for producing open patterns have been made by embedding cardboard baiiles in the shot charge for scattering the shot and these 'bafiles have resulted-in :the, production of much confetti and other debris which is of great annoyance to the shooter. Suchbafiles also separate the shot into distinct groups, with gaps between groups. However, as pointed out .above, by using a wad column of improved gas sealing properties in aroll crimp .shell, the shot will be effectively anduniformly-scattered by the top wad alone and with a substantial reduction in confetti-over known types of scatter loaded shells.

"Filler wadsof wad-columns may bemade from some form of hair felt, such for example as the felt "described in the patent to Burghardt, No. 1,724.3.38, August 13, 1929.; or may be molded from a suitable compositionof fibrous and/or granularmaterials, as described/in the patents to Woodford, No. 2,-026,-7 65,-J anuary 7, 1936, and Ernst, No. 1,659,649, February 21,1928. The material and/ or configuration -of the "wad column must be so chosen that the column as a whole has a certain amount ofcompressibility. The necessity for this arises from the fact that a comparatively heavy mass '(1 to 1% .02,) of lead shot :must be set in motion. Uponr-ignition of the powder the pressure -r-ises very rapidly, and .if the wad column doesnot yield to :acertain extent during the initial-movement of the shot .mass, excessively high and=somewhat dangerous powderpressures are developed, andtheresulting hammer blow applied to the stationary shot mass will cause severe shot abrasion,-rleformation-, excessiveleading and poor patterns.

in one aspect, the present invention contemplates -a.filler wad column so'prepared as to furnish both a-n improved gas .seal and a yieldable pressure-transmittingcushion. To this end, a

relatively rporousvand compressible wad, such as a wad of the type shown :in the patent to WoodforcL-is impregnatedwith azmedium adapted to quitecompletely'fill all voids andinterstices therein, and .having lubricating properties. Appropriate impregnantsrare high melting'point waxes of animal, vegetable, :mineral or synthetic origin. Suitable waxesfor waddmpregnation may include such petroleum derivatives as .the higher melting point .-paraifin waxes and the products commerciallyknown ias Barnsdall wax and So'cony 2300, the latter being a microcrystalline petrolatumwax; --hydrogenated animal and vegetable derivatives with melting points higher than 120 Fesuch as :hydrogenatedsoy bean oil, hydrogenated cottonseedoil, and thewaxes commercially known as Armour #1 and Armour #2; and synthetic wax-like materials, prominent among which-are the San'to waxes. By melting point it is .meant todefine the point-at which the wax has melted to a degree which permits significant amounts .to vrun or migrate from the body of the wad. A lu'bricating wax which will not run into the powder at temperatures below-120 F. is suitable.

vAlthough otherfibrousfelted structures of suitable strength. may be used, a wad of the .type shown in the Woodford patent ishig'hly suited to this application byJreason. of its non-laminar felted characteristics. As pointed out .infthe Woodford patent, a characteristic of many felted completely prevent laminar separation.

orientation achieved in the practice of the Woodford process serves to reinforce the wad and to When such a fibrous felted structure has been completely impregnated, as discussed in the preceding paragraph, itcombines in one body the characteristics of strength, plasticity and lubricating effectiveness necessary to permit the elimination of the "usual overpowder wad of heavy cardboard.

As set forth above, it has been found undesirable to impregnate the entire wad. column, by reason of the fact that wads thoroughly impregnated are substantially incompressible and-tend to produce high. pressures. Pressures become excessive and patterns are undesirably scattered when more than about of the entire filler wad column is impregnated. On the other hand, when lessthan about 10% of the wad column is impreg nated, gasleakagebecomes excessive. The requf sites of commercial practice indicate that the im ,pregna'ted portion o'fthe wad column should 'be between'30% and 70% thereof, the remainder being unimpregnated.

.Apre'ferired form of wad column is one comprising two superposed wads, the lower wad being thoroughly impregnated with one of the aforementioned hardening and lubricating waxes and the upper wad comprising any. conventional 'unimpregnated compressible material. The upper wadmay be provided with the conventionalrim lubrication. It willbe understoodhowever, that the wad column vmay comprise other than .two wads, as, for example, a single wadthe lower .portion .of which is thoroughlyimpreg-nated with a high .melting point wax; or three or more superposed wads, the impregnated portion .of the wad eo1umn-being 30% -.to 70% of the height of the column. -Moreover, it will be noted that the preferred W-adcolumn does not include the usual cardboard overepowder wad whichhas been deemed necessary -.to. prevent break-up of the soft .filler wads, and itself disintegrates into an undesir-able cloud of small particles.

Wad columns constructed in accordance with this invention have superior gas sealing properties as a-consequence of which shot charge turbulence has .been substantially eliminated with an accompanying reduction of barrel leading to as low as that which has characterized the best .gas .sealingwadcolumns heretofore known. Moreover, the superior zgas sealing properties of the impregnated wad column obviate the loss of energy duefltoigas leakage, andenable desired pressures and velocities .tobesecured withsmaller powder charges. iMoreover, by eliminating the cardboard over-powder wad, the potentially troublesomelpaperiparticles or confetti are substantially reduced.

.Asheret'ofore stated, the conventional shots'hell as -manu$actured for the-market in this country comprises .-a body :of wound paper. To secure additional.strengthaswell as for moisture :proofing, the paper body is heavily .impregnatedwith avwax such as paraffin wax. Commercial .shot shells may be .stored .for substantial periods at temperatures such .esltosubstantially soften the body impregnate .and cause apart of suchimpregnate to vflow into the contents of the shell including the .powder. .Theeffect of such .migrated waxon thepowder.isdefinitelydetrimental and .the .present invention contemplates the use, in conjunction with the improved wad column heretofore described, of suitable devices for protecting the powder charge from the body wax.

Various means for powder protection are illustrated in the drawings. The shot shell of Fig. 1 comprises the conventional metallic head If) containing the battery assembly H and receiving the end portion of the wax impregnated paper body l2. The body contains a charge of propellent powder l3 and superposed thereon a wad l4 impregnated as heretofore described. Upon the impregnated wad I4 is placed a rim-lubricated wad l5 of any conventional deformable material. The wads l4 and 15 may vary somewhat in thickness to provide the desired ratio of impregnated portion to unimpregnated portion. Above the wad I5 is theusual shot charge l6 preferably held in place by a closure 11 integral with the body 12 and sealed by a disk l8 adhering thereto.

The base wad 20 is of improved construction comprising an elongated circumferential skirt 2| adapted to extend up the wall of the body l2 sufiiciently high to enclose the entire powder charge.

The base wad is preferably rolled from a strip of paper which is crinkled or otherwise provided with corrugations, as shown in Fig. 4, so that the completed wad will have an elasticity comparable to the elasticity of the body of the shot shell. By providing a base wad having an elasticity comparable to the elasticity of the body of the shell, localized splitting of the wad when under high gas pressures and especially at low temperatures is substantially eliminated thereby obviating rupture of the body of the shell. The skirt of the base wad may be formed in situ during the heading operation by using a punch of somewhat less overall diameter than the diameter of the wad, thereby allowing several plies of the wad adjacent the body of the shell to remain uncompressed.

The base wad and skirt are preferably of a relatively dry and somewhat pervious material, and hence the skirt 2| provides a medium for absorbing such wax as may leave the juxtaposed portion of body l2 under high temperature storage, thus preventing such wax from reaching the powder l3. The wax impregnate of the wad l4 superposed on the powder charge l3 has a relatively high melting point (above 120 F.) and hence will not flow into the powder even under the most extreme storage conditions. As an alternative construction, the base wad and its skirt may be properly treated by coating or impregnating with a suitable wax impervious lacquer varnish or similar medium of high melting point to insulate the powder from the migratory body wax.

Fig. 2 illustrates another means of shielding the powder charge from body wax. The shell comprises wads M and I5, similar to those described in conjunction with Fig. 1, and a base wad 25 having any desired powder contacting configuration. A nipple 26, which is preferably a short section of a dry fiber or paper tube, is fitted within the body l2 and extends from the end of the circumferential portion of base wad 25 to the adjacent face of filler wad 14. Such nipple 26 provides a medium for absorbing body wax when necessary and preventing movement of such wax into the powder. Although a paper tube has proven satisfactory, a tube comprising any suitable wax impervious material may be used.

Fig. 3 illustrates a shot shell body so prepared as to prevent the migration of wax into the powder without the use of such a separate shielding medium as is shown in Figs. 1 and 2. To the inner surface of the portion of the shell body which contacts the powder, between the top of the base wad and the face of the impregnated filler wad l4, there is applied a coating 28 of a wax impervious lacquer varnish or other suit able medium. The shell body so prepared is assembled with the other components of a shot shell in the usual manner.

The powder protecting devices shown will be understood to be illustrative only. By means of the combination of impregnated and non-impregnated filler wads and powder shielding devices, shot shells, particularly flat top shot shells having high power loads, have been produced which consistently show excellent patterns and acceptable maximum pressures, both when fresh and after storage under very severe conditions. Moreover, when fired these shells produce substantially no confetti and relatively little or no leading.

What is claimed is:

1. A filler wad column positioned between the shot charge and the powder charge of a shot shell comprising a compressible cushioning portion seated against the shot and a piston portion seated against the powder, said piston portion comprising a fibrous felted body substantially completely impregnated with a waxlike lubricating material which will not run at temperatures below F.

2. A filler wad column positioned between the shot charge and the powder charge of a shot shell comprising a compressible cushion wad seated against the shot and a piston wad seated against the powder, comprising a fibrous felted body substantially completely impregnated with a waxlike lubricating material which will not run at temperatures below 120 F.

3. A filler wad column positioned between the shot charge and the powder charge of a shot shell comprising a compressible cushion wad seated against the shot and a piston wad seated directly against the powder, said piston wad comprising fibrous, non-laminar felted body substantially completely impregnated with a waxlike lubricating material which will not run at temperatures below 120 F.

4. A filler wad column positioned between the shot charge and the powder charge of a shot shell comprising a compressible cushion wad seated against the shot and a piston wad seated directly against the powder, said piston wad being not substantially less than 30% nor more than 70% of the height of the entire wad column and comprising a fibrous felted body substantially completely impregnated with a waxlike lubricating material which will not run at temperatures below 120 F.

WALTER L. FINLAY. GILBERT E. HUTCHINSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,771,897 ONeil et al July 29, 1930 2,336,065 Cadham Dec. 7, 1943 FOREIGN PATENTS Number Country Date 4,178 Great Britain 1902 116,757 Germany Jan. 21, 1901 230,235 Great Britain Mar. 12, 1925 478,030 Great Britain Jan. 11, 1938 

